<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>数组扩展方法</title>
</head>
<body>
  <script>
     const arr=[1,2,3,7,89]
    //  console.log(Array.prototype);
     Array.prototype.max=function(){
         return Math.max(...this)
     }
     console.log(arr.max())
  </script>
</body>
</html>